Concern & action: Actual U-value?

Performance gap between the modelled U value for any building element and its actual thermal performance can be considerable. Inaccurate modelling can lead to incorrect specification of measures and unexpected energy use outcomes.

Suggested actions

Before Implementation

Physically measure U-value or conductivity of fabric elements (e.g. walls) prior to determining insulation strategy. Consult tables of measured in situ U-values for similar wall constructions of similar thickness. Consider adjustment to overall refurbishment strategy if measured U-values are found to be significantly better than the calculated U-values to those quoted in official literature.

During implementation

After implementation

Consider another measurement post-insulation to assess effect. Feedback measured data to add to knowledge of building elements performance.